Suction fan wheel



Nov. 7, 1933. M, WEBER 1,

SUCTION FAN WHEEL Filed Jan. 6, 1933 2 Sheets-Sheet 1 Nov. 7, 1933. M.WE BER SPUCTION FAN WHEEL Filed Jan. 16, 1933 2 Sheets-Sheet 2 PatentedNov. 7, I 1933 UNITED STATES PATENT" orrica SUCTION FAN WHEEL Max Weber,(Ihicago, 111. Application January 16, 1933. Serial No. 651,874 7Claims. (01. 170-159) The present invention relates generally to fanwheels of the suction variety. More particularly, the invention relatesto that type of suction fan wheel which is adapted to operate in air orother bodies of gaseous or aeriform fluid and to be driven at acomparatively high speed from any suitable source of power, andcomprises a hub and a plurality of blades which are connected to andradiate from the hub and are angularly disposed with respect to theplane of rotation of the Wheel so that they serve duringdrive of thewheel to draw the air or fluid from the front of the wheel and force itrearwardly under pressure and at increased velocity from the back side.

One object'of the invention is to provide a suction fan wheel of thetype under consideration in which the hub tapers to a point at the frontside of the wheel, that is, in front of the suction faces of the blades,and is so formed that it 20 eliminates pressure resistance in front ofthe hub and serves to deflect the air upwardly and rearwardly into thepath of the rear or pressure faces of the blades.

Another object of the invention is to provide a fan wheel of the lastmentioned character in which the tapered front part of the hub hascurved surfaces which form at the root or inner end parts of the bladescontinuations of the suction surfaces and operate during drive of thefan wheel to produce a suction effect whereby the air directly in frontof the hub is drawn into position for contact with the 'pressure facesof the blades, and also to assist rotation of the fan wheel when thewheel is moved forwardly at high speeds, such, for example, as is thecase when the wheel is used in connection with the cooling of anautomobile'motor.

A further object of the invention is to provide a suction type fan wheelin which the blades are of such number and are so shaped and constructed that rotation or form resistance, as well as frictionresistance, is reduced to a minimum, and they permit the wheel to bedriven at comparatively high speeds without noise and with anexceptionally low power consumption in proportion to the amount of airor fluid displacement.

In addition, it is contemplated as one of the objects of the inventionto provide a fan wheel of the suction type which is generally of new andimproved construction, may be produced at a low and reasonable cost andis extremely efiicient in operation.

Other objects of the invention and the various advantages andcharacteristics of the present fan construction will be apparent from aconsideration of the following detailed description.

The invention consists in the several novel features which arehereinafter set forth and are more particularly defined by claims at thecon- 6 clusion hereof.

In the drawings which accompany and form a part of this specification ordisclosure and in which like numerals of reference denote correspondingparts throughout the several views:

Figure 1 is a side view showing a fan wheel embodying the inventionapplied to an automobile motor;

Figure 2 is a front view of the fan wheel;

Figure 3 is a horizontal section taken on the line 3-3 of Figure 2 andillustrating in detail the cross sectional construction .of the hub andpulley which is connected to and forms an integral part of the rear endof the hub;

Figure 4 is an enlarged front the blades of the fan wheel;

Figure 5 is a transverse section taken on the line 5-5 of Figure 4 andillustrating in detail the construction and shape of the hub surfaceswhich form continuations of the inner end portions of the suction facesof the blades and serve, during drive of the fan, to produce a suctionefiect whereby the air directly in front of thehub is drawn intoposition for contact with the pressure faces of the blades;

Figure 6 is a transverse section taken on the line 6-6 of Figure 4 andshowing the cross sectional shape and the angularity of the blade at theroot portion, that is, at the point where the blade is joined to orunited with the hub;

Figure 7 is a transverse section taken on the line 7-7 of Figure 4 andshowing the cross sectional shape and the angularity of the blade atapproximately one-sixth of the way from the inner end of the blade tothe outer end;

Figure 8 is a transverse section taken on the line 8-8 of Figure 4 andshowing the cross sectional shape and the angularity of the blade atapproximately one-third of the way from the inner end of the blade tothe outer end;

Figure 9 is a transverse section taken on the line 9-9 of Figure 4 andshowing the cross sectional shape and the angularity of the blade atapproximately one-half of the way from the innerend of the blade to theouter end; 105

Figure 10 is a transverse section taken on the line 10-10 of Figure 4and showing the cross sectional shape and the angularity ofthe blade atapproximately two-thirds of the way from the inner end of the blade tothe outer end; and

View of one of 7 Figure 11 is a transverse section taken on the line1111 of Figure 4 and showing the cross sectional shape and theangularity of the blade at approximately five-sixths of the way from theinner end of the blade to the outer end.

The fan wheel which forms the subject matter of the invention is of thesuction variety or type and is adapted to be used in connection with themoving of air or other bodies of gaseous or aeriform fluids. It consistsof a hub 12 and five blades 13 and, for purpose of illustration, isshown in Figure 1 of the drawings in connection with an automobile A.The automobile A is shown more or less diagrammatically and embodies aframe or chassis F upon the front end of which is mounted a motor M anda radiator R. The motor is of the internal combustion type and embodiesat one side thereof an intake manifold I and a carburetor C. Theradiator R is mounted on the frame or chassis F in front of the motorand is connected to the water jacket of the motor M so that the watercirculates therethrough for cooling purposes, as well understood in theart. The fan wheel is located directly behind the radiator and isadapted during drive thereof to draw air through the radiator and forceit rearwardly around the motor M. It is carried by a horizontallyextending stub shaft S which extends longitudinally of the frame of theautomobile and has the rear end thereof supported rotatably in a bracketB. The latter is fixedly secured to the front end of the motor M. Thefront end of the stub shaft extends into an open-ended, cylindricalsocket 14 in the rear end of the hub 12 of the fan wheel and is securedfixedly to the hub for fan wheel-driving purposes by means of a pin, keyor set screw (not shown). The fan wheel is driven by means of an endlessbelt 15. This belt extends around and is driven by a circular element orpulley 16 on one of the operating shafts of the motor, such, forexample, as

the cam shaft, and extends around and serves todrive a pulley 1'7 at therear end of the hub of the fan wheel. When the motor M is in operation,the fan wheel is driven through the medium of the belt 15 and thepulleys 16 and 17 and operates to draw air through the radiator R and toforce it rearwardly around the motor M for cooling purposes. The pulley1'7, as shown particularly in Figure 3 of the drawings, is formed as anintegral part of the hub 12 and consists of a pair of annular flanges 18and 19 which are spaced apart to form a groove for the belt 15. Theflange 18 is located in front of the flange 19 and embodies a front face20 which is conical and is so tapered that it unites with the hub at thecentral portion thereof. By employing the conical face 20, the air whichis projected rearwardly by the fan wheel is deflected slightly outwardlyin order to produce a more efficient cooling of the space behind theradiator R.

The fan wheel is preferably in the nature of a one piece aluminumcasting although if desired it may be formed of molded compositionmaterial or it may be drop forged, stamped or otherwise formed; Theblades 13 radiate from the central portion of the hub 12 and are spacedequal distances apart. By virtue of the fact that there are five blades,each blade extends at an angle of 72 with respect to the two adjacentblades. The blades 13 embody suction faces 21 at the front thereof andpressure faces 22 at the back, and are angled with respect to the planeof rotation of the fan wheel so that the suction faces operate duringdrive of the wheel to draw air rearwardly throug the radiator R intocontact with the pressure faces 22. The latter in turn, effect rearwardpropulsion of the air around the motor M. The pressure faces are in theform of longitudinally or helically twisted flat surfaces and at themotor inner ends of the blades extend rearwardly at an angle of 42 withrespect to the plane of rotation, as shown in Figure 6.- At one-sixth ofthe distance from the .inner ends of the blades to the outer ends, the

pressure faces 22 are inclined or angled at 40 with respect to the planeof rotation. At onethird of the distance from the inner ends of theblades to the outer ends, the pressure faces extend rearwardly at anangle of 37 /2 with respect to the plane of rotation, as shown in Figure8. Halfway between the inner and outer ends of the blades, the pressurefaces extend rearwardly at an angle of 35 with respect to the plane ofrotation of the fan wheel. At two-thirds the way from the inner ends ofthe blades to the outer ends, the pressure faces extend rearwardly at anangle of 32 Az from the plane of rotation. At fivesixths of the way fromthe inner ends of the blades to the outer ends, the pressure facesextend rearwardly at an angle of 30 with respect to the plane ofrotation of the fan wheel, as shown in Figure 11. By virtue of the factthat the pitch of the pressure faces of the blades decreases 2 /2 everysixth of the distance from the inner ends of the blades to the outerends and the pressure faces at the root or inner end parts of the bladesare inclined rearwardly at an angle of 42 /2" with respect to the planeof rotation, each blade, during rotation of the fan wheel, produces acolumn or stream of air which flows spirally. By reason of the fact thatfive blades are employed, the fan wheel produces five distinct helicalor spiral columns of air which flow around the motor in the mannerindicated by arrows in Figure 1 of the drawings. An advantage andcharacteristic of developing spiral or helical streams of air around themotor M is that there are no dead air spots around the motor and. acontinuous supply of fresh air to the carburetor C is assured. Anadditional advantage or characteristic of having the blades of the fanwheel arranged and shaped so as to produce spiral streams of air is thatmaximum efficiency is obtained with respect to cooling of the motor Mand the air behind the radiator is constantly evacuated. By forming thepressure faces of the blades in the manner hereinbefore set forth,friction resistance is reduced to a minimum. The conical front face 20of the flange 18 of the pulley 17 operates, as previously' pointed out,to deflect outwardly the air emanating from the pressure faces of theblades 13 and results in the helical or spiral streams of air beingdeflected so that they envelop and travel around substantially allportions of the motor.

The leading edges of the blades 13 are substantially straight, as shownin Figures 2 and 4. The extreme outer or tip portions of the blades arerounded and are substantially semi-circular in conformation. Thetrailing edges of the blades are curved and the central portions of theblades are slightly less than one-half the length of the blades.

The suction faces 21 of the blades are convex, as particularlyindicatedin Figures 6, '7, 8, 9, 10 and 11. The blades are of maximumthickness near the leading edges thereof and the suction faces 21 aresharply curved adjacent the leading edges. The portions of the suctionfaces adjacent to the trailing edges of the blades are more graduallycurved. The shape or conformation of the suction faces 21 is such thatduring rotation of the fan wheel, the air is drawn into contact with thepressure faces 22 at low velocity. A further attribute or characteristicof the specific shape or conformation of the suction faces of the bladesis that form or rotational resistance is reduced to a minimum and thereis no noise produced during drive of the fan wheel at high speeds.

In order to destroy pressure resistance in front of the hub of the fanwheel and to increase the efiiciency of the wheel, the front end of thehub is formed so that it tapers forwardly to a point or apex part 23 andembodies around the periphery thereof five curved surfaces 24. Thesesurfaces are located between the root or inner end' parts of the blades13 and extend from the apex part 23 to substantially the central portionof the hub. They are concave and slant rearwardly in a direction opposedto that of rotation of the wheel. The front portions of the surfaces 24are shaped so that they are in the nature of continuations of theleading edges of the blades 13 and extend from the apex part 23 to theleading edges of the blades. The side portions of the surfaces 24 join.the suction faces 21-of the blades and are in the nature ofcontinuations thereof. In addition, they operate to produce suctionduring rotation of the fan and are shaped so that the air which is drawninto contact therewith by suction effect, is directed to the pressurefaces 22 of the blades. By shaping the front end of the hub so that ittapers to a point or apex part 23 and embodies the rearwardly extending,curved or arouate faces 24, pressure resistance in front of the fanwheel is eliminated and the front end of the hub operates, during driveof the fan wheel, to draw the air at the center of the wheel rearwardlyand to project or direct it into contact with the pressure faces of theblades which, as previously pointed out, force the air rearwardly inhelical or spiral streams. The rear portions of the surfaces 24 join theconical front face 20 of the flange 18 in arcuate lines 25, as shown inFigures 2 and i. The surfaces 24, in addition to increasing theefficiency of the fan wheel, reduces the power necessary to drive thewheel at high speeds in that the air impinging thereagainst has atendency to rotate the fan. One of the features of shaping the blades sothat the pressure and suction faces are of the character described isthat the air is drawn through all portions of the radiator uniformly andat a low velocity with the result that efficient cooling of the water inthe radiator is effected.

When the motor M of the automobile, is in operation and the fan wheel isdriven by way of the endless belt 15 and the pulleys 16 and 17, thesuction faces 21 of the blades 13 operate to draw air from in front ofthe radiator R through the radiator and into contact with the pressurefaces 22 of the blades. These last mentioned faces, as previouslypointed out, deflect the air rearwardly at an increased velocity and inthe form of five,

spiral or helical streams which flow around the motor M. This spiral orhelical flow of the air streams around the motor serves to cool themotor and in addition, insures a fresh supply of air to the carburetorC. The work of the suction faces 21 of the blades 13 of the fan wheel isaugmented by the curved, rearwardly slanting surfaces 24 on the frontend of the hub. These surfaces, as previously-pOinted out, produce asuction effect during drive of the fan wheel and direct upwardly intothe path of the pressure faces of the blades, the air directly infrontof the fan wheel. As a result of the hub formation, there is little, ifany, pressure resistance as far as the fan wheel is concerned, and but aminimum amount of power is necessary to drive the fan wheel at highspeeds due to the torque produced by the surfaces 24 of the hub inresponse to impingement of air thereon. By employing five blades insteadof four or six or any other number, the fan wheel is harmoniouslybalanced.

In practice it has been found that a twenty cubic feet of air per minuteand requires an input of approximately 0.563 horse power to drive it; at2000 revolutions per minute, the fan displaces approximately 6480 cubicfeet of air per minute and requires an input of approximately 1.186horse power to driveit. At a speed of 800 revolutions per minute, atwenty inch, five bladed fan of the character herein specified drivesthe air at approximately 12.15 miles per hour; at 1200 revolutions perminute, it drives the air at approximately 21.70 miles per hour; at 1600revolutions per minute, it drives the. air at approximately 26.40 milesper hour; and at 2000 revolutions per minute, it drives the air at avelocity of approximately 36.90 miles per hour. These results aredirectly attributable to the fact that the blades are five in number andare constructed to reduce to a minimum form and friction resistance, andthat the front end of the hub substantially eliminates pres sureresistance and is shaped to augment the work of the blades by virtue ofthe fact that it includes the curved surfaces 24.

Whereas the fan wheel has been shown and described in connection withdrawing air through the radiator of an automobile and forcing itrearwardly around the automobile motor, it is to be understood that thewheel may be used for other purposes and in diiferent ways. It is alsoto be understood that the invention is not to be restricted to thedetails set forth, since these may be modified within the scope of theappended claims, without departing from the spirit and scope of theinvention.

Having thus described the invention, what I claim as new and desire tosecure by Letters Patent, is:

1. A wheel for rotation in a fluid, embodying means whereby it may beconnected for rotation by a source of power and comprising an elongatedhub and a plurality of angularly disposed blades connected to andradiating from the central portion of the hub and having suction andpressure faces at the front and rear sides of the wheel respectively andarranged so that during rotation of the wheel they operate to suck thefiuid from in front of the wheel and project it rearwardly, the frontend of the hub being tapered to a point so as to destroy pressureresistance and embodying concave surfaces extending between the root or:inner end parts of the blades and to the point r and shaped to suckrearwardly the fluid directly in front of the hub and deliver itoutwardly and rearwardly into the path of, and contact with the pressurefaces of the blades in response to wheel rotation.

and arranged angularly with respect ,to the plane of rotation of thewheel and to suck the fluid from infront of thewheel and project itrearwardly during rotation of the wheel, the front end of the hub beingtapered in order to destroy pressure'resistance and embodying concavesurfaces joining and forming continuations of the suction faces of theblades and operating during rotation of the wheel to suck rearwardly thefluid directly in front of the. hub and deliver it outwardly andrearwardly into contact with the pressure faces of the blades.

3. A wheel for rotation in a fluid, comprising an elongated hub providedat the rear end thereof with a pulley whereby thewheel may be beltdriven and a plurality of angularly disposed blades connected to andprojecting radially from the central portion of the hub and havingsuction and pressure faces at the front and rear sides of the wheelrespectively and for drawing or sucking the fluid' from in front of thewheel and projecting it rearwardly during. rotation of the wheel, thefront face of the. pulley being tapered towards the, central portion ofthe hub and, serving to deflect outwardly the fluid projected rearwardlyby the inner or root portions of the pressure faces of the blades.

4. A wheel for rotation in a fluid, comprising an elongated'hubprovidedat the rear end thereof with a circular element whereby the wheel may bedriven, and a plurality of'angularly disposed blades connected to andprojecting radially from the central portion of the hub and havingsuction and pressure faces at the front. and rear sides of the wheelrespectively for drawing or sucking the fluid from in front of the wheeland projecting it rearwardly during rotation of the wheel, the frontface of the circular element being tapered towards the central portionof the hub and serving to deflect outwardly the fluid projectedrearwardly by the inner or root portions of the pressure faces of theblades.

5. A wheel for rotation in a fluid, comprising an elongated hub providedat the rear end thereof with a circular element whereby the wheel may bedriven, and a plurality of angularly disposed blades connected to andprojecting radially from the central portion of the hub and havingsuction and pressure faces at the front and rear sides of the wheelrespectively for drawing or sucking the fluid from in front of the wheeland projecting it rearwardly during rotation of the wheel, the front endof the hub being tapered in order to destroy pressure resistance infront of the wheel and embodying surfaces for sucking rearwardly thefluid directly in front of the hub and delivering it outwardly andrearwardly into contact with the pressure faces of said blades, and thefront face of the circular element being tapered towards the centralpart of the hub and serving to deflect outwardly the fluid projectedrearwardly by the inner or root portions of said pressure faces of theblades.

6. A wheel for rotation in a fluid, embodying means whereby it may beconnected for rotation by a source of power and comprising an elongatedhub, and a plurality of angularly disposed, equidistantly spaced bladesconnected to and radiating from the central portion of the hub andhaving suction and pressure faces at the front andrear sides of thewheel respectively for drawing or sucking the fluid from in front of thewheel and projecting it rearwardly during rotation of the wheel, thefront end of the hub being tapered substantially to a point so as todestroy pressure resistance'in front of the wheel and embodying concavesurfaces which slant rearwardly in a direction opposite to that ofnormal rotation of the wheel and join and form continuations of the rootportions of the suction faces of the blades and operate during rotationof the wheel to suck rearwardly the fluid directly in front of the huband deliver it outwardly and rearwardly into the path of, and contactwith, the pressure faces of the blades.

7. A one-piece fan wheel for rotation in one direction in a fluid,embodying means whereby it may be connected for drive by a source ofpower and comprising an elongated hub, and a plurality of angularlydisposed blades formed integrally with and radiating from the centralportion of the hub and having suction and pressure faces at the frontand rear sides of the wheel respectively and .for drawing the fluid fromin front of the wheel and projecting it rearwardly during rotation ofthe wheel, the front end of the hub' being substantially pyramidal inconformation in order to destroy pressure resistance in front of thewheel and having the side surfaces thereof corresponding in number tothe blades, slanting rearwardly in the opposite direction to that ofrotation of the wheel, joined to the root or inner portions of thesuction surfaces of the blades and operating during rotation of thewheel to suck rearwardly the fluid directly in front of the hub anddeliver it outwardly and rearwardly into the path of, and contact with,the pressure faces of the blades.

MAX WEBER.

